1. Field of the Invention
This invention relates to the wiring which distributes electric power to various receptacles, switches and fixtures in a home or other building, specifically the means for containing and stabilizing connections among wires or between wires and switches or receptacles.
2. Description of the Related Art
Early 20th century patents (671 763; 832 508; 832 509; 1 264 450; 1 473 812) indicate that electrical junction boxes for wiring homes and other buildings have changed little for a century with respect to dimensions and functionalities, because those characteristics are very suitable for the intended purposes. Recently, polymers have been used in junction-box manufacture, but steel remains the dominant material.
Typically, the floor and side walls of a junction box have several cable ports with knockout plugs, any of which may be opened for installation of a cable clamp or conduit adaptor. Some junction boxes have cable clamps already in place at a few cable ports. In any case, the cut ends of cables must be threaded into a junction box via these entry points before connections are made. Installing the most common kind of cable clamp in a cable port is often tedious, and threading a cable into a junction box via the most common kind of built-in cable clamp is often tedious as is tightening of that kind of clamp. Making connections among wires confined at their points of entry into a junction box is often tedious, and connecting such confined wires to a receptacle, switch or other device can be tedious. Moreover, there are occasions where one desires to connect conductors of cables which have not been cut through completely, and this is very awkward with conventional junction boxes. The junction box disclosed herein facilitates all of these tedious and awkward operations by allowing an already connected wire-to-wire junction or an already wired-up device to be placed in the box as its cables are laid in their respective ports, any of which may have an associated clamp which is built on to the box.
The applicant has not seen a manufactured junction box with this capability and has not found a patent for a junction box able to accept an already connected branch junction (involving three or four cable ports and clamps). The applicant did find two patents for junction-boxes which would allow placement of an extension junction, a switch or a receptacle (involving no more than two cables) in the box after its connections are made. The junction box of Park (4 051 322) is fabricated as two hemiboxes which come together side-by-side at a seam through the floor and two opposite side walls. The hemiboxes are hinged to each other along the floor seam. The seam intercepts a cable port on each of two opposite side walls, and these two cable ports are opened radially when the box is opened at the seam. The design provides for only two ports able to accept the cables of a preformed junction. It appears that the concept could have been extended to a second seam and hinging means transverse to the first, by having two hinges symmetrically placed on each floor seam rather than one, thereby providing four radially openable cable ports. Park's design envisioned conduit attachments and did not show built-in cable clamps. The hinged junction box appears to be relatively expensive. The junction box of Yahruaus (4 818 822) for containing a receptacle or switch consists of two side-by-side hemiboxes, each with a hemiport contiguous with the assembly seam on each end of each hemibox. This design allows one to assemble the box and ports (with their built-in clamping means) around a wired-up device and the cable(s) thereto or to assemble the box and ports around an extension junction and its two cables. The side-by-side arrangement of partial boxes seems less suitable for branch junctions (needing three or four cable ports and cable clamps), since four ports formed this way would involve four quarter-boxes (a more complicated assembly, possibly with insufficient rigidity). The patents of Park and Yahraus are the only ones the applicant could find of house-wiring junction boxes able to accept a preformed junction, and neither has the capabilities of the one disclosed herein.